Heat exchanger



vNov. 26, 1935. D. P. HEATH v HEAT EXCHANGER Aoriginal Filed April-11, 1951 Patented Nov. 26, 1935 lPATENT OFFICE HEAT EXCHANGER Delos P. Heath, Detroit, Mich.

Application April 11, 1931, serial No. 529,334

Renewed March 22, 1935 12 Claims. (Cl. (i2-126) This invention relates to heat exchangers which operate with one or more iluids under pressure.

It is an object, to provide a two chamber integral vessel by assembling corrugated metallic plates contiguous to, but on opposite sides of, a common metallic central wall so that a compact heat exchanger ofhigh thermal eiiciency may be arranged as a relatively thin walled structure.

It is an object to provide processes whereby sheet metal heat exchangers may be manufactured at lower cost than the cost of present devices for this purpose.

In the drawing:

Figure 1 is a plan view of the assembled heat exchanger with a plurality of headers connected by a plurality of passageways.`

Figure 2 is a section along line 2-2 of Figure 1.

Figure 3 is a sectional view of Figure 1 along line 3 3.

Figure 4 is a modiilcation showing a sectional end view along line 3-3 of a modiiication of Figure 1 which has a dished sheet in place ofthe corrugated sheet 8. y

Figure 5 lis a plan view of a modiilcation of Figure 1 showing a sinuous passage-way.

Figure 61s a section along line 6--6 of Figure 5.

Figure 7 is a section along line 'I-l ofv Figure 5.

Figure 8 is a section of a modiication of Figure 5 showing a section along line 6-6 one of the plates in Figure 5 mated with a plate of Figure 1.

Figure 9 isla section taken on a horizontal plane through Figure 8; and

Figure 10 is a sectional View similar to Figure 2 showing the sheet metal structure bent to provide a plurality of walls of an enclosure or compartment.

Like numerals refer to like parts.

In the description of the drawing in detail, I,

designates a thin metallic sheet corrugated with a plurality of passage-ways, 2, connected by flat portions, 3, and also corrugated with the headers, I` and 5, which communicate with passages 2. B are inlet openings and 'I are outlet openings in the heat exchanger structure. 8 is a corrugated sheet mating with sheet I, but on the opposite side of the metallic sheet II which is contiguous with portions of both sheets I and' or brazed together, I prefer to fuse them to each other by the welding process.

A single chamber of this heat exchanger resembles the corrugated steel structure shown in my Patent Number 1,726,486, dated August 27, 5 1929, and my patent application, Serial Number 75,325 of December 14, 1925.

The usual heat exchangers for fluids under pressure comprise a plurality of double pipe constructions or a pipe in contact with a pressure l0 wall. 'I'he improvement contained in this invention lies in the forming of corrugations in at sheets and assembling three sheets together so that the fluids in the heat exchanger are spread out in a relatively thin stream and are directed .l5 by the corrugations so that a counter iiow circulation may be maintained to provide an increased rate of heat transfer in a structure of relatively low cost. l i

In Figure 4, in a modication, the sheets I and II are rst welded together between the corrugations and then the dished sheet, I3, is welded to i and II to form the two iiuid tight chambers. This construction of the heat exchanger does not permit the use of high pressure in the chamvber 9 in'view of the fact that the wall, I3, is not welded between its peripheries.

In Figure 5, the corrugations of Figure 1 are modiiied to provide the sinuous corrugations I2, in the sheets I4 and I5. The similar sheets, il 30 and I5, are mated on opposite sides of sheet Il, and the three sheets are Welded together as explained before. This structure may be bent after welding, to provide a plurality of walls of an enclosure or compartment or the sheets may be bent before assembling.

It is also practicable in forming this heat exchanger to advantageously utilize the many other shapes of corrugations, having various cross-sectional forms, in the outside sheets. The corrugation may be, for example, arranged into a spiral or it might be formed with an increasing crosssectional area.

As shown in Figures 8 and 9 various combinations of corrugated plates may be welded up to provide passage-Ways peculiarly suited for the various states of the fluids in the heat exchanger.

Y The corrugated sinuous plate, I4, in these figures,

is mated or paired with the plate 8, which is corrugated with the plurality of headers and a plurality of connected passage-ways. The iiuids in the adjacent chambers of the sheetmetal heat exchangers may be either liquids or gases, or a combination of both. The sinuous coil, I3, of Figure 8, for example, may contain a condensing gas and the corrugations 2, 4 and 5 may contain a liquid boiled by the heat received from the adjacent chamber through the wall, Il.

While I have shown in Figure 10 the structure disclosed in Figure 2 as being bent to provide a plurality of walls of an enclosure or compartment it is obvious that any of the modiiled structures disclosed may also be bent ln a similar manner. It is to be understood therefore, that any of the structures disclosed may be bent to provide a heat exchange unit of any desired form or configuration. For example my improved heat exchange unit may be utilized as an evapora tor of a refrigerating system, in which case it is desirable to bend the unit to provide an enclosure or compartment adapted to receive receptacles containing a substance from which heat is to be extracted by the unit.

In operation, uids possessing a difference of temperature or a difference of heat energy enter the openings, t, and circulate in counter-flow direction relative to each other, and then pass out through outlets, 1, with the difference of temperature or in heat energy of the outlet fluids less than that of the incoming uids. 'I'his result is obtained through the loss of heat from the warmer fluid to the colder iiuid through the metallic middle wall, it. As this wall is relatively thin, has a smooth surface, and is integrally xed to sheets, i and 8, at close intervals, it exchanges heat by conduction at a high rate. Also the relative small size of the passage-ways provided by the corrugations secures the high velocity of fluid flow to break down the fluid films at the surfaces of the sheets, thus increasing the overall coefficient of heat transfer by reducing the thickness of these films.

If the unit is utilized as an evaporator of' a refrigerating system the fluid passages on each side of the middle plate may be connected in series s`o that the fluid passing through the unit first flows through the passages adjacent the inner wall of the compartment formed by the unit and then through the passages on the outer side of the middle plate. Thus a refrigerating iiuid flowing through the unit first removes heat from the freezing compartment formed by bend ing the unit into the desired shape `and then absorbs heat from the air adapted to flow over the unit.

I claim:

1. A sheet metal evaporator for a refrigerating system comprising in combinationa plurality of metallic plates, each plate having corrugations forming communicating passageways, a substantially fiat plate having its opposite sides secured to said flrst named plates between the corrugations in said plates and at their peripheries, said three plates forming two independent refrigerant expansion chambers having a common wall therebetween, and a refrigerant inlet and a refrigerant outlet for each of said chambers.

2. A sheet metal evaporator for a refrigerating system comprising in combination, a plurality of metallic plates, each plate having corrugations forming communicating passageways, a substanf tially fiat plate having its opposite sides secured to said first named plates between the corrugations in said plates and at their peripheries, said three plates forming two independent refrigerant expansion chambers having a common Wall therebetween, a refrigerant inlet and a refrigerant outlet for each of said chambers, and said plates extending around a plurality of sides of a freezing compartment.

3. A sheet metal evaporator for a refrigerating system comprising in combination, a metallic plate corrugated with a plurality of headers and between formed by said middle plate, and a re- 10 frigerant inlet and a refrigerant outlet for each of said chambers.

4. A sheet metal evaporator for a refrigerating system comprising in combination, a metallic plate corrugated with a plurality of headers and connecting passageways, an indented metallic plate, a substantially at middle metallic plate, said corrugated plate, indented plate and middle plate being secured together at their peripheries and forming two independent closed refrigerant expansion chambers having a common wall therebetween formed by said middle plate, and a refrigerant inlet and a refrigerant outlet for each of said chambers, and said plates extending around a plurality of sides of a freezing compartment.

5. A sheet metal evaporator for a refrigeratconnecting passageways, a substantially fiat me- 30 tallic middle plate, va metallic plate corrugated with a sinuous passageway, said corrugated plates being secured between their corrugations and at their peripheries to opposite sides of said middle plate ind forming two independent closed refrigerant expansion chambers having a commonwall therebetween formed by said middle plate, and a refrigerant inlet and a refrigerant outlet for each of said chambers.

6. A sheet metal evaporator for a refrigerating system comprising in combination, a metallic plate corrugated with a plurality of headers and connecting passageways, a substantially flat metallic middle plate, a metallic plate corrugated with a sinuous passageway, said corrugated plates being secured between their corrugations and at their peripheries to opposite sides of said middle plate and forming two independent closed refrigerant expansion chambers having a common wall therebetween formed by said middle plate, and a refrigerant inlet and a refrigerant outlet for each of said chambers, and said plates extending around a plurality of sides of a freezing compartment.

7. A sheet metal evaporator for a refrigerating system comprising in combination, a pair of metallic plates corrugated with sinuous passageways, a substantially fiat metallic middle plate, said corrugated plates being secured between their corrugations and at their peripheries to opposite sides of said middle plate and forming two independent closed refrigerant expansion cham` bers having a common wall therebetween. and a refrigerant inlet and a refrigerant outlet for each of said chambers. l

8. A sheet metal evaporator for a refrlgerating system comprising in combination, a pair of metallic plates corrugated with sinuous passageways, a substantially fiat metallic middle plate, said corrugated plates being secured between their corrugations and at their peripheries to opposite sides of said middle plate and forming two independent closed refrigerant expansion chambers having a common wall therebetween, and a refrigerant inlet and a refrigerant outlet for each of said chambers, and said plates, extending around a plurality of sides of a freezing compartment.

9. A sheetmetal evaporator fora refrigerating system comprising in combination, a pair of metallic plates, a substantially flat metallic middle plate, said pair`of plates each being secured throughout their peripheries to opposite sides of said middle plate and having portions thereof intermediate their peripheries spaced from said middle plate and forming two independent closed refrigerant expansion chambers having a common wall therebetween formed by said middle plate, and a refrigerant inlet and a'refrigerant outlet for each of said chambers.

10. A sheet metal evaporator for a refrigerating system comprising in combination, a pair of metallic plates, a substantially flat metallic middle plate, said pair of plates each being secured throughout their peripheries to opposite sides of said middle plate and having portions thereof in- A termediate -their peripheries spaced from said middle plate and forming two independent closed refrigerant expansion chambers having a common wall therebetween formed by said middle plate, and a refrigerant inlet and a refrigerant loutlet foreach of said chambers, and said plates extending around a plurality of sides of a freezing compartment. Y.

11. A sheet metal evaporator for a refrigerat` ing system comprising, a pair of metallic plates,

a third plate interposed between said pair of plates, at least onel of-'said plates having corrugationsl formed therein, said three plates being secured together at their peripheries and between said corrugations to provide communicating passageways, said three plates forming two independent refrlgerant expansion ducts or chambers having a common wall therebetween, and

a refrigerant inlet and a refrigerant outlet vfor each of said ducts or chambers.

, 12. A sheet metal evaporator for a refrigerat' ing system comprising, a pair of 'metallic plates, a third plate interposed between said pair of plates, at least one of said plates having corruga' tions formed therein, said three plates being secured together at their peripheries and ibetween said corrugations to provide communicating passageways, said three plates forming two independent refrigerant expansion ducts or chambers having a common wall therebetween, a refrigerant inlet and a refrigerant outlet for .each of said ducts or chambers, and said plates being bent after being secured together to provide said 25 evaporator with a plurality of walls of a freezing compartment.

' v DELOS P. HEATH. 

